Absorption apparatus



March 17, 1936. J A T NKlRcg Re. 19,888

ABSORPTION APPARATUS Original Fiied June 8, 1929 Reissued Mar. 17, 1936UNITED STATES 19,888 'ABSORPTION APPARATUS Edmund Altenkirch,Neuenhagen, near Berlin, Germany, assignor, by mesne assignments, to TheHoover Company, North Canton, Ohio, a

corporation of Ohio original application June 8, 1929, Serial No.369,358, Patent No. 1,887,957, dated November 15, 1932. Divided andapplication October 9, 1930, Serial No. 487,465, Patent No. 1,887,909,dated November 15, 1932. Application torreissue October 11, 1934, SerialNo. 747,858. In

Germany June 16, 1928 26 Claims. (0]. 62-1195) My invention relates toabsorption apparatus.

It is known in the art to' constru continuously operating absorptionapparatus, particularly refrigerating apparatus in such a manner thatthe differences of pressure between the evaporator and the absorber onthe one hand and between the generator and the condenser or resorber onthe other hand are more or less equalized by the presence of a neutralor inert gas in the evaporator and absorber. In the known absorption apparatus the absorption solutions as well as the neutral gas arecirculated in closed circuits. The present application is a continuationin part of my co-pending application for patent Serial No. 369,358,filed June 8, 1929, on which Patent 1,887,957 was granted November15,1932, and for which application 745,929 filed September 28, 1934' isan application for reissue; The present subject matter relates moreparticularly to an absorption apparatus of the kind mentioned, in whichthe gaseous working medium 'or refrigerant development in a generator isabsorbed in a resorber by an absorption solution and is evaporated in anevaporator from the absorption solution. In

contrast .to the hitherto known absorption apparatusythe delevopment ofthe gaseous working medium in the generator takes place-at leastpartly-4n the presence of a neutral gas.

The-advantage obtained by the presence of neutral gas in the generator,is as follows:

The mixture of gaseous'working medium and neutral gas entering thegenerator may be so proportional that the partial pressure of the.gaseous working medium is very low. Generation of gaseous working mediumcan then be effected without having to raise the final temperature ofthe generator as high as is necessary with generators without anadmixture of gas. .The extensive degasification of the absorptionsolution is of great importance for good absorbing action in theabsorber. The reduction of the final temperature of the generator isalso useful on account of the danger of decomposition of the gaseousworking medium (e. g'. ammonia) at high temperatures, such as areordinarily necessary, particularly with air-cooled absorptionrefrigerators.

tween that vessel and a resorber.

The inert gas in the generator may circulate be- If, however, severalgenerators and several absorbers are employed, a generator and anabsorber may be connected together to form a circulation system for gasmixture. It is also possible to connect one or more" generators with aresorber and one or moreabsorb'ersas to form a common system for thecirculation of gas mixture. Best results are obtained if the gas mixtureis made to circulate in counterflow to the absorption solution, so thatgenerator. As an indifferent gas, one heavier than.

the gaseous working medium may be employed.

Accordingly, it is one object of the invention to provide a continuousabsorption refrigerating system with an arrangement for circulatinginert gas through the generator. 1

It is another object of' the invention to provide an absorptionrefrigerating system capable of wide variation in operatingcharacteristics, such as quantity heat input, temperature of heat input,capacity, operating efliciency, etc.

Further details, possibilities of construction and advantages of theinvention are contained in the following description, and in theaccompanying drawing, which illustrates the invention, in partschematically, and partly in a form approaching the actual construction;In all figures of the drawing, the manner in which the individualvessels are connected with one another is illustrated. The arroweddash-dot lines represent gas mixture circuits, the arrowed continuouslines represent liquid circuits. I

Fig. 1 is the diagram of an absorption apparatus in which an absorberand an evaporator are connected with one another to form a gas-mixturecirculation system, and a generator and a resorberto form anothergas-mixture circulation system, and in which the circulation of theabsorption solution of the one range of concentration leads'through thegenerator and the absorber and that of the other range of concentrationthrough'the resorber and the evaporator.

Fig. 2 is the diagram of an absorption refrigere ating apparatus, inwhich a generator and a resorber, a second generator and an absorber anda second absorber and an evaporator are connected together respectivelyin pairs, each of the the two generators and'with both absorbers so astoconstitute a common gas-mixture circulation system, while the resorberand the other generator are free of indifferent gas. Fig. 4 is thediagram of an absorption apparatus suitable for the discharge of heat ata high temperature, with one generatoao'ne' absorber, one resorber andone evaporator, i. e. with the same constituent parts as in Fig. 1, butin which all the vessels are connected with one another to form a singleliquid circulation system and to form a single, closed gas-mixturecircuit.

Fig. 5 is the diagram of an absorption refrigcrating apparatus with onegenerator, two absorbers, one resorber and-one evaporator, in which thegenerator is connected with the resorber and one of the two absorbers,and the other absorber with the evaporator in such a manner that each ofthe groups forms a closed gas-mixture circulating system, and i Fig. 6shows an absorption refrigerating apparatus constructed in accordancewith the present invention. It illustrates the arrangement of thesolvent consists of sulphuric acid, the working various vessels andconnecting pipes substantially in the form of a practical apparatus.

In the following description, the invention wi be described as appliedto the production of refrigeration although it is to be understood thatit is not limited in this respect. Throughout the specification andclaims where the words "workrefrigerant content is meant but wheresulphuric acid is specifically mentioned for use as absorbent and wateras refrigerant, the concentration will be referred to herein asconcentrated or strong when the sulphuric acid content is high.

The essence of the invention is simple to explain with reference to theschematic Fig. 1. In

that figure the generator is indicated by K, the

absorber by A, the resorber by R and the evaporator by E. .Let usassume, for example, that the medium of water, the neutral gas in thegenerator and resorber of nitrogen, and that in the evaporator andabsorber of hydrogen, and furof water to a great extent, flowing fromthe generator K to the absorber A exchanges its heat with the solutionenriched with working medium and flowing from the absorber to thegenerator. We also assume that the very watery solution, flowing fromthe resorber to the evaporator exchanges heat with the solution comingback from the evaporator to the resorber. For simplicity, the heatexchange has not been indicated in the drawing; but might be inferredfrom.'the close proximity of the pertaining lines.

The absorption machine schematically illustrated in Fig. 1 operates asfollows:

when heat is imparted to the aqueous sulphuric acid solution in thegenerator K, steam develops into the admixed nitrogen. The sulphuricacid,

which has become more concentrated owing to sorber R where it gives upto the sulphuric acid solution coming from the evaporator E the steamwhich it took from the generator. The absorption heat produced iscarried oil! by cooling water or air, The gas mixture more or lessdeprived of steam returns to the generator K, whereas the sulphuricacid, weakened by the water it has taken up, passes into the evaporatorE, where it gives up to the admixed hydrogen the steam it contains andthereby producesuseful refrigeration. In doing so the gas mixturebecomes heavier and descends into the absorber A, where the steam isabsorbed by the concentrated sulphuric acid coming from. the generatorK; the heat produced-thereby being here also carried away by coolingwater or air. The gas mixture which is now freed from steam and has beenheated in the absorber rises again into the evaporator. In all vessels,the absorption" solution and the gas mixture flow, as shown by arrows,in counterilow to each other.

The total pressure in the two gas circulation systems may be different,or may be the same. If it is different, the difference of pressure ismaintained in a known manner. for instance, by means of liquid columns.For example in case of an underpressure in the absorber the latter wouldbe placed higher than the generator, and if there is an underpressure inthe evaporator, it would be placed higher'than the resorber.

It simplifies matters, if in the different gasmixture circulationsystems neutral gas of the same kind is used, and the total pressure ismaintained at an equal value in both systems.

Thegaseous working medium is absorbed in the resorber from the gasmixture by the solution at-a partial'pressure corresponding to thetemperature of the cooling means. From the solution it again evaporatesinto neutral gas in the same range 'of concentration in a zone of alower partial pressure. It has hitherto been assumed that the gaseousworking meansis developed in the generator at a pressure correspondingto the partial pressure of the resorber and was fed to the neutral gas.The invention however gains considerably in importance if a third(higher) pressure zone or partial pressure zone is provided, in whichgaseous working medium is developed and liquefied, the latter forinstance through absorption in a resorber. This zone of highest pressuremay be used with or without indifferent gas. I

The arrangement of the-third zone of higher pressure permits aconsiderable reduction of the temperature of the heat supplied. Thisreduction is, for instance of advantage where the absorption apparatusisoperated with waste heat.

Assuming the refrigerant is generated in the presence of an indifferentgas, the refrigerant pressure, at which this takes place may be higherthan that at which it is absorbed, butlower than the pressure at whichthe liquefying or resorption takes place. This case is illustrated inFig. 2 of the drawing. The generation and absorption ofthe gaseousworking medium takes place here in two separate pressure stages. Forthis purpose, besides an evaporator E and a resorber R, two generatorsK1 and K: as well as two absorbers A1 and A: are provided. With thisarrangement, it is made possible for the working medium generated in thegenerator K2, in the medium partial pressurezone. instead of going intoa condenser or resorber, to pass into the absorber A1 through the agencyof the indifferent gas, into which it was developed when separate inertgas circuits.

being generated. In the absorber A1 it is reabsorbed in presence ofindifferent gasat a medium temperature and a medium partial pres- Isure. As the partial pressure in the absorber A1 corresponds to thepartial pressure in the generator K2 and is, therefore, considerablyhigher than in the absorber A2 (which is connected with the generator K2so as to form a liquid circulation system, and the partial pressure ofwhich corresponds to the partial pressure in the evaporator E), thesolution in A1 will be considerably more enriched with working medium.

Consequently, the temperature in the generator K1 operating at a stillhigher-partial pressure can be considerably reduced, without impairingthe evaporator temperature.

In the arrangement of Fig. 2, there are three separate absorptionsolution circuits and three In each solution circuit the refrigerant isabsorbed from inert gas at one temperature range and at one refri erantpartial pressure zone and expelled into inert gas at another temperaturerange and another partial pressure zone. In each solution circuit theconcentration of solution varies over the same concentration rangeduring the absorption and expulsion. That is, the same amount ofrefrigerant is expelled from any one solu tion circuit as is absorbed bythat circuit.

By controlling the inert gas partial pressures in the three inert gascircuits, the refrigerant partial pressure in the evaporator E, and theabsorber A2 is maintained low; the refrigerant partial pressure in theboiler K2 and the absorber A1 is maintained at amedium or intermediatepressure; and the refrigerant partial pressurein the boiler K1 andresorber R is maintained high.

The absorption solution circulating between the absorber A2 and theboiler K2 has a low range of refrigerant concentration; that circulatingbetween the absorber A1 and -the boiler K1, a medium or intermediaterange of refrigerant concentration; and that circulating between theresorber R and the evaporator E, a high range of concentration. In anycontinuous absorption system means must be provided for transferring therefrigerant from the low refrigerant pressure zone of the evaporator tothe high refrigerant pressure zone of the resorber (in this connection acondenser may be regarded as a special form of resorber) The arrangementof Fig.

2 provides what may be termed a multistage or compound boiler-absorberfor doing this. The refrigerant absorbed in the absorber A: is expelledin the boiler K2 and conveyed into the absorber A1 to be there absorbedinto a solution of a higher refrigerant concentration range than that inthe absorber A2. The refrigerant absorbed in absorber A1 is expelled inthe boiler K1 and conveyed to the resorber. gas is present in boiler K2,the refrigerant partial pressure in this vessel is low and the boiler K:can operate at a relatively low temperature. Because the solutionsupplied to the boiler K1 is of a refrigerant concentration higher thanit would be if it were coming'directly from absorber A2, it likewise canoperate at'a relatively low temperature.

If the arrangement of Fig. 2 is modified so that inert gas is eliminatedfrom the boiler K:

and resorber R, acondenser substituted for the resorber and the twosolution circuits through the multi-stage boiler absorber systemcombined sorber A1 back to the absorber A2.

into one, the arrangement of applicants copendingapplication Serial No.692,373 filed October 6, 1933 (now Patent No. 2,000,005 granted June 7,1935) is obtained. The system of this copending application. maytherefore be said to embody a specific form of the present invention.

If the system of Fig. 2 is operated as a heating means instead of arefrigerator, a high temperature of the heat outputcan be obtained.

It is only important that there should be a generator, in which thepartialpressure, at which the gaseous working medium is developed fromthe solution of the same concentration range into the indifferent gas,is higher than the partial. pressure at which the working medium isabsorbed from the gas mixture by the solution, but is at the same timelower than the pressure or partial pressure, at which the liqu'efying orresorption preceding the evaporation or de-gasiflcation takes place inthe. working medium circuit.

The solution circuit of the intermediate concentration range (that whichincludes the absorber A1 and boiler K1) of Fig. 2 may be combined withthe solution circuit 'of high refrigerant concentration range (thatwhich includes the resorber R and the evaporator E) Fig. 3 illustratesaspecial adaptation of such a system A liquid circuit connects thegenerator K2 of the medium partial pressure zone to the absorber A: ofthe lowest partial pressure zone. A second liquid circuit traverses thegenerator K1, the evaporator E, the resorber R and the absorber A1 inseries. Thus the solution with lower refrigerant content, flows from theevaporator E directly to the generator K1.

The lowest partial pressure zone includes the evaporator E and absorberA2, and the medium partial pressure zone includes generator K2 andabsorber A1. This gas mixture flows from the absorber A1 to theevaporator E, from there to the generator K2 and finally through the ab-The absorption solution flows, as the arrows show, in the range of thestronger refrigerant concentration, from resorber R into evaporator E,from there into the generator K1, then into absorber A1 and finally backinto resorber R. A perfect operation of this absorption refrigeratingmachine presupposes, as a matter of course, a good exchange of heatbetween the absorption solutions as well as between the gas mixtures,which circulate obtained by combining all of the liquid circuits intoone, and all of the gas mixture circuits into one. Fig. 4 shows such asystem. Because inert Heat is transmitted at a mean temperature to thegenerator K and to the evaporator E. The

absorption solution flows, as the arrows show,

from E into the resorber R, where it meets the gas mixture which isenriched by gaseous working medium in the generator K. By the absorptionof the working medium from the gas mixture in the resorber R, heat ofhigh. temperature is produced which can be delivered to the outside. Thegas mixture in the resorber R, partially freed 'of the working mediumpasses now into the absorber A, operating at a low temperature, where,in a low partial pressure zone of the working medium, the solutionenriched by the workenriched from the gas mixture. The solution isv thenreturned at a mean temperature, to the generator K for the purpose ofrenewed develop- I ment 8, 85860118 working medium. The 898 mixture inthe absorber A, freed to a great extent of the working medium passesinto the evaporator E, and through the heat of a mean temperature bringsabout a thorough degassing of the absorption solution in the latter. Thegreatly impoverished absorption solution will be thereby capable, whenreaching resorber R, to absorb therein working medium from the rich gasmixture supplied from generator K.

In order thatacomparatively great amount of heat of hightemperature maybe produced with the least possible extraction of heat at lowtemperature supplied from outside it is indispensable that the liquid aswell as the gas mixture form closed circuits. that they exchange heatwith one another and that they be dimensioned properly with regard'totheir quantities as required for the various concentration ranges andpartial pressure zones.

Fig. shows schematically an absorption re-' frigeratlng system in whichthe two liquid circuits of the two absorber systems of Fig. 2 arecombined. Likewise two of the three circuits which, in Fig. 2 areindependent, are combined, the gas mixture circuit between the mediumand the low temperature range remaining separate. The absorbers remainseparated but the two gen- I erators of Fig. 2 are combined into one.

A number of the gas mixture circuits, described above, run through achamber of especially high temperature. the gas mixture. This isparticularly true for the generator of thehlgher partial pressure zoneand for the resorbers. Care should be taken, by means of a heat[exchanger between the gas mixture flowing to the generator or theresorber and gas mixture flowing from the generator or the resorber andgas mixture flowing from the generator or the resorbernot to havevaluable heat carried oil or the cold lost. It should, howgas mixturecircuitsdisclosed, the partial pressure range, which they traverse intwo or three dliferent pressure zones, is so considerable, that thequantity of the circulating gas involved may be comparativelyinsignificant. For this reason a heat exchanger between'the circulatinggas mixture'may be .dispensed with in many cases 7 without great loss.The same applies also to the circulation of the absorption solutionbetween the various temperature ranges. I

For the, circulation of the absorption solution various means can beemployed, all of which are well known i'or'similar'purposes. If forinstance the pressure in the chambers. where working medium under highpressure is absorbed from the gas mixture, is higher than in thechambers of the same liquid circulating system,-where gaseous workingmedium is developed out of the absorption solution into the neutral gas,this diflerence of pressure can be maintainedby means of liquidcoiumnsicolumns' of.fiowing absorption solution) a A liquid circuit isthen established as a result of the diflerent speciflc weights of therich and of the poor solution. In cases in which the several gas mixturecircuits are combined. it is not possible to maintain such a diflerenceof pressure. In order to bring about the desired liquid circulation the'diiierent vessels should then be connected by some means such as U-pipes which may races 'Ihis'iacilitates the circulation of observed;that. with the majority of the exchange heat with the indiiferent gas.The circulation may be brought about by heating the solution in therising limb of the U-pipe. which carries the solution for instance intothe chamher, which belongs to' the higher temperature range.

An example of this type of liquid circulation is given in thearrangement according to Fig. 6, which will be explained in thefollowing: I The absorption apparatus shown in Fig. 6 is" one somewhatlike that schematically illustrated in Fig. 2. Similar to Fig. 2, anevaporator and a resorber are provided, and two generators and twoabsorbers. The evaporator is connected with the resorber by a liquidcirculating system for the absorption solution of the higher refrigerantconcentration range. Each of the two generators is connected with itsrespective absorber by a liquid circulating system for absorptionsolution. The evaporator is connected to one of the two absorbers so asto forma gas mixture circulating system. Inert gas also circulatesbetween the other absorber and one of the two generators, and betweenthe other generator and theresorber.

The arrangement of'Fi'g. 6 diflers from that in Fig. 2 in the manner inwhich the inert gas circulates inv the zones of intermediate and highrefrigerant partial pressure. In the arrangement of Fig. 2 the inert gascircuits in these two zones are maintained separate, one inert gascircuit including K: and A1 (the zone of intermediate refrigerantpartial pressure) and another inert gas circuit including K1 and R (thezone of high refrigerant partial pressure). In Fig. 6, these twocircuits are combined although the vessels forming a part thereof. arenot connected in series. All of the inert gas which flows through theresorber of Fig. 6 passes through the absorber which corresponds to theabsorber A1 of Fig. 2' and through the boiler which corresponds to theboiler Krof Fig. 2. From this boiler, the inert gas divides, partflowing to the boiler which corresponds to K1 of Fig. 2 and part flowingtothe absorber, which corresponds to A1. The system is not the same asthat 0! Fig.2, therefore, but is a modification of it.

In l'ig.'6,-l is the generator of the highest partial pressure zone;heated by two heating elements 1. Like the other vessels it is of thehorizontal type and, like the other vessels, the connections are, suchthat a counter current of gas mixture and absorption liquid results. Theabs.

, it flows back into the generator I by means of a liquid pipe I whichis in heat exchange relation with the pipe 3. The circulation is causedby a heating element 0 arranged in the lower part of the rising limb, ofthe pipe I. The heating element can be connected to an electrical sourceof energy. I

Likethe vessels I and l, the generator I of-the,

medium partial pressure zone, (heated by heat in'g elements 1) and theabsorber-g8 of the partial pressure zone are connected by means of whichare in heatthe liquid pipes Ill and II, exchange relation with oneanother. l2 denotes a heating element, arranged on the rising limb oithe U-shaped liquid pipe l|. From the resorber It the absorption liquidflows through a liquid pipe I4 intothe evaporator 15 and thence throughthe liquid conduits It, i1, is to the resorber i3. The conduit I]surrounds-the pipe The pipe I8 is U-shaped. The rising limb can beheated by means of a heating element I9. The absorbers is connectedtm-the, evaporator by the gas pipes 20 and 2I. The inlets of these pipesinto the gas chamber of the vessels 9 and I are such that, anindiiferent gas (for instance hydrogen) which is lighter than thegaseous working medium (for instance ammonia), circulates automaticallyas a result of the difference in the molecular weights and as aresult'of the changes ranges of temperature can be easily added to thosealready described. This improvement may be of great importance if, forinstance, by adding the third pressure zone, a low evaporatortemperature is maintained at one place but with of the specific weightof the gas columns, caused by the diiference in temperature. Thegenerator I l is connected to the resorber I3 by means of a gas pipe 22,which delivers the gas mixture, enriched with gaseous working medium, tothe resorber.

For carrying off the indifierent gas from thev resorber I3, a gaspipe-23 is connected to the top of absorber 4. From the absorber 4 a gaspipe 24 runs to the generator 8 and from this generator a gas pipe 25runs to the top of absorber I, where it joins the aforementioned gaspipe 23. A further gas pipe 26, which branches of! from the pipe 25,connects with generator I.

' It is assumed that the inert gas in the circuit which includes thevessels I, 4, 8 and I3 is heavier than the refrigerant gas, and that therefrigerant is ammonia. The gas mixture in the vessels I and B, in whichthe ammonia vapour 'is developed'and admixed to the indifferent gas,will be lighter than in the vessels of thesecircuits, in which it isdeprived of the greater part of ammonia by absorption. Moreover sincevessels I and 8 lie in the highest range of temperature the rising ofthe gas mixture to the resorber I3 or absorber 4 will be favoured bywhich flows upward through the pipe 25-is divided into two parts. Onepart flows through the pipe 26 to the generator I, pipe 22, resorber I3and the pipe 23, into absorber 4, while the other part flows directly toabsorber A, at the top of which it again joins the part flowing throughpipe 23, In this manner a greater amount of gas mixture circulatesthrough the vessels I and 8 than through the vessels I and I3,

the heating in the generators. 'The gas current Besides thisparticularexample of a combination of several gas mixture cycles, a number of inthis respect.

It is possible in the case of an absorption refrigerating apparatuswhich possesses, as illustrated in Fig. 4, two generators and twoabsorbers but only one evaporator and one resorber-to combine thegenerator of the highest pressure stage, operating without admixture ofthe indifferent of the absorption solution of the second concenothermodifications of the invention are possible as (such as K1 in Fig. 4)with the second generator and both absorbers in a liquid circulatingsystem, which is completely separated from the liquid circulatingcircuit, in which liquid of the other concentration range circulates. Inthis case it is possible tohavetwo gas mixture circulating circuits,separatedue from another,

one of. which connects the evaporator and one of. the two absorbers withone another in the low partial pressure zone, and the other of whichincludes both absorbers as well as the generator oithe middle partialpressure zone.-

In the above mentioned examples three ranges of temperature areinvolved, between which the absorption solutions or gas mixturescirculate.

"The invention is not, however, limited thereto.

As it is possible without difllculty for two different'evaporatortemperatures or two entirely difierent generator temperatures tocoexist, other this case therefore we deal with four ranges oftemperature.

If it is of importance to lower the temperature slightly for theproduction of cold or to considerably .reduce the generator temperature,the in tended effect rnay be obtained by adding other pressure orpartial pressure zones so far as it lies within the'limits ofpracticability.

I claim as my invention:

1. In an'absorption machine containing a working medium, a solvent forsaid medium and an indifierent gas not absorbable by said solvent, agenerator'system comprising a plurality of generators, at least onegenerator being used for developing gaseous medium from absorptionsolution of a-first concentration'range, a resorber system comprising atleast one resorber for,

absorbing said developed gaseous medium into absorption solution of asecond concentration range, an evaporator for evaporating working mediumfrom the absorption solution of the second concentration range, anabsorber for absorbing'evaporated gaseous medium to form absorptionsolution of the first concentration range, pipes .connecting theaforementioned elements to form a closed circulation system for saidworking medium, connecting pipesbetween the generator system and saidabsorber to permit circulation of the absorption solution of the firstconcentration range, connecting pipes between the resorber system andsaid evaporator to permit circulation tration range, the evaporation ofworking medium in the evaporator, and the absorption of gaseous mediumin the absorber occurring in the pres ence of said indifierent gas, thedevelopment of first concentratiomrange occurring in at least a portionofthe generator system in the presence of indiiferent gas;

i 2 'In an absorption machinecontaining a work; ing medium, a. solventfor 'said' medium and an indifferent gas not absorbable by said solvent,a generator system comprising a, plurality of generators, at least onegenerator-being used for developing gaseous medium from absorptionsogaseous medium from absorption solutionof the lution of a firstconcentration range, a. resorber system comprising at least one resorberfor absorbing said .developed'gaseous medium in absorption solution of asecond concentrationv range, an evaporator for evaporating working,

ond concentration range, an absorber for absorbing evaporated gaseousmedium to form absorpvtion solution of the first concentration range,

pipes connecting the individual parts of the abmedium from theabsorption solution of the secsorption machine to form a closedcirculation system for said working medium, connecting pipes betweensaid generator system and said necting pipes between the said resorbersystem and said evaporator to permit circulation oi the absorptionsolution 01' the second concentration range, the evaporation of workingmedium in the evaporator, and the absorption of gaseous medium in theabsorber occurring in the presence 01' said indiflerent gas, thedevelopment of gaseous medium from absorption solution oi! the firstconcentration range in the generator system occurring in the presence ofindiflerent gas, and connecting pipes between at least a portion of thegenerator system and at least a portion of said resorber system torender possible circulation of the indiflferent gas through a generatorand a resorber;

3. In an absorption machine containing a working medium, a solvent forsaid medium and an indiflerent gas not absorbable by said solvent, agenerator system comprising at least one generator for developinggaseous medium from absorption solution, a resorber system comprising atleast one resorber for absorbing gaseous medium in absorption solution,an evaporator for evaporating working medium from the absorptionsolution, an absorber for absorbing gaseous mediumto form absorptionsolution, pipes connecting the individual parts of the absorptionmachine to form a circulation system for said working medium,-saidsolvent and said gas, the evaporation or working medium in saidevaporator, and the absorption of gaseous medium in said absorberoccurring in the presence of said indifierent gas, the development 01'gaseous medium from absorption solution in at least a part oi saidgenerator system, occurring in the presence of indifi'erent gas,isaidconnecting pipes including connections between that part 01 saidgenerator and said absorber to permit circulation of the indifferent gasthrough said part oi! the generator the second concentration range, anabsorber for absorbing said evaporated gaseous medium to form absorptionsolution of the first concentration range, pipes connecting theindividual parts ing pipes between said generator system and saidabsorber to permit circulation oi the absorption fsolution oi the firstconcentration range, conevaporator and the absorption of gaseous mediumin said absorber occurring in the presence of said indiflerent gas, thedevelopment of gaseous medium irom absorption solution oi the firstconcentration range in at least a part 01' said generator systemoccurring in the presence of indiiierent gas, and connecting pipesbetween said part 01' the generator system,'said resorber and saidabsorber to render possible a circulation oi the indiflerent gas throughsaid generator part, said resorberand said absorber.

5. In an absorption machine containing a working medium, a solvent forsaid medium and an indiflerent gas not absorbable by said solvent, agenerator system comprising at least one generator for developinggaseous medium from absorption solution of a first concentration range,

a resorber system comprising at least one resorber for absorbing saiddeveloped gaseous medium in absorption solution of a second concenin thepresence of saidindiflerent gas, the dey velopment of gaseous mediumfrom absorption solution of the first concentration range in at least apart of said generator system occurring in the presence of indifferentgas, and connecting pipes between said part of the generator system,said evaporator and said absorber for establishing a uniform circulationof the. indifferent gas through said vessels.

6. In an absorption machine containing a working medium, a. solvent forsaid medium and an indifierent gas'not absorbable by said solvent, agenerator system comprising a plurality of generators, at least onegenerator being used for developing gaseous medium from absorptionsolution of a first concentration range, a resorbersystem comprising atleast one resorber for ab sorbing developed gaseous medium in absorptionsolution of a second concentration range, an evaporator-for evaporatingworking medium from the absorption solution of the second concentrationrange, an absorber for absorbing evaporated gaseous medium in absorptionsolution of the first concentration range, pipes connecting theaforesaid-parts to form a closed circulation system for said workingmedium, connecting pipes between said generator system and said absorberto permit circulationv of the absorption solutionof the firstconcentration range, connecting pipes between the saidresorber systemand said evaporator to permit circulation of the absorption solution [ofthe second concentration range, the

evaporation oigaseous medium in the evaporator and the absorption ofgaseous medium in the absorber occurring in the presence 01' saidindifferent gas, the development 01 gaseous medium from absorptionsolution of the first concentration range in at least a portion of saidgenerating system occurring in the presence of indifferent gas, thedevelopment of gaseous medium in the generator system and its conversioninto a more dense fluid phase occurring at a partial pressure higherthan the partial pressures of the gaseous working medium in the othervessels.

'7. In an absorption machine containing a working medium, a solvent forsaid medium and an indifferent gas not absorbable by said solvent, agenerator system comprising a plurality of. generators at least onegenerator being used for developing-gaseous medium from absorption so--lution of a first concentration range, a resorber system comprising atleast one resorber h g1) sorbing the developed gaseous medi evaporatorfor evaporating working medium from the absorption solution of thesecond concentration range, an absorber for absorbing curring in thepresence of indifierent gas, the de- J evaporator 'ior evaporatingevaporated gaseous medium in absorption solution of the firstconcentration range, pipes connecting the aforementioned parts to form aclosed circulation system for the said working medium, connecting pipesbetween said generator system and said absorber to permit circulation ofthe absorption solution of the first concentration range, connectingpipes between the said resorber system and said evaporator to permitcirculation of the absorption solution of the second concentrationrange, the evaporation of working medium in the evaporator and theabsorption of gaseous medium in the absorber'occurring in the presenceof said indifierent gas, the development of gaseous mediumfromabsorption solution of the first concentration range in at least aportion of said generator system ocvelopment of gaseous medium in thegenerator system, and its conversion into a more dense fluidvphaseoccurring at a partial pressure higher than the partial pressuresof the gaseous working medium in the other vessels, and said gasdevelopment occurring at a higher temperature than the gasdevelopmentand absorption in the other vessels.

8. An absorption machine having a generator for developing gaseousworking medium from an absorption solution of a first concentrationrange, an absorber forabsorbing working medium'by an absorption solutionof rthe same con+ centration range, a second generator and asecond-absorber for respectively developing working medium from, andabsorbing it into absorption solution of .a second concentration'range,an working medium from absorption solution of a third concentrationrange, a resorber for absorbing said evaporated medium to formabsorption solution of said third concentration range, the gaseousworking medium in said generators, absorbers, evaporator and resorberhaving an indifferent gasadmixed to it, connecting pipes between the,said first generator and said resorber, connecting pipes between saidsecond generator and said first'absorber and between said secondabsorber and said evaporatorto form gaseous mixture circuits through thevessels connected .with one another. 9. An absorption machine,containing a generator and anabsorber, a. second generator and a secondabsorber, an evaporator and aresorber,

saidflrstgeneratorbeing connected with said first absorber, saidresorber and said evaporator so as to form a common .circulation circuitfor absorption solution,'said second generator being connected with saidsecond absorber to form a second circulation circuit for absorptionsolution, the gaseous working medium in the said .two absorbers, thesaid second generator and the 'said evaporator having indifferent gasadmixed to it, and connecting pipes between the saidlast named vesselsto permit circulation of indifferent gas through them.

' evaporator and resorber to permit circulation of absorption solutionthrough said two vessels, connecting pipes between said two generatorsand said two absorbers to permit circulation of absorption solutionthrough the last-named vessels, the gaseous working medium in saidevapsaid other absorber and 'said generator.

11. An absorption refrigerating machine, containinga generator, aresorber, an evaporator and two absorbers, connecting pipes between saidevaporator and said resorber to permit circulation of absorptionsolution through said last-named vessels, connecting pipes between saidgenerator and one of said absorbers to permit circulation of solutionthrough said generator and said absorber, the gaseous working medium inall said vessels having indifierent gas, admixed to it, connecting pipesbetween said evaporator and said one of said absorbers to establishcirculation of indifferent gas through said lastnamed vessels,connecting pipes between said partial pressure zone, while the othergenerator and the otherabsorber belong to a medium par-' tial pressurezone, connecting pipes to permit circulation of absorption solutionbetween said resorber and said evaporator, connecting pipes forestablishing a second solution-circuit including said first generatorand said second absorber, and connecting pipes for establishing a thirdsolution circuit including said second generator and said firstabsorber,the gaseous working medium in all of said vessel having indifferent gasadmixed to it, conecting pipes between said evaporator and saidfist-mentioned absorber for establishing circulation of gas mixturethrough the lowest partial pressure zone vessels, connecting pipesbetween said second generator and said second ab- 1 'sorber'forestablishingcirculation of gas mixture through the medium partialpressure zone vessels, connecting pipes between said first generator andsaid resorber for establishing "circulation of gas mixture through thehighest partial pressure zone vessels, and an intermediate connectionbetween the gas circulation systems of the highest and 01' the mediumpartial pressure zone, whereby the amount of mixture flowing through onezone is made different from the amount flowing through the other zone.

13. An absorption'refrigerating machine, havingseveral different partialpressure zones in its constituent vessels and containing two generators,a resorber, an evaporator and two absorbers, one

. of said generators and said resorber belonging to a high partialpressure zone, and one ofsaid absorbers and said evaporator belonging toa low partial pressure-zone, while the other generator and the otherabsorber belong to a medium partial pressure zone, connecting pipes topermit circulation of absorption liquid between said resorber and saidevaporator, connecting pipes for establishing a second liquid circuitbetween saidfii first generator and said second absorber, and connectingpipes for establishing a third liquid cir-'- cuit between said secondgenerator and said first absorber, the gaseous working medium in all ofsaid vessels having indifierent gas admixed to it, connecting pipesbetween said evaporator and said first-mentioned absorber forestablishing circulation of gas mixture through the lowest pare tialpressure-zone vessels,-connecting pipes between said second generatorandsaid second absorber for establishing circulation of gas mixturebetween the medium partial pressure zone vessels, connecting pipesbetween said first generator and said resorber for establishingcirculation of gas mixture between the highest-partial pressure zonevessels, and an intermediate pipe connection mtween the gas circulationsystems of the highest and the medium partial pressure zone, whereby areciprocal action occurs between the absorption solution and the totalamount 01. indifferent gas mixture in the medium partial pressure zone,but whereby only a portion of this total amount takes part in thereciprocal action with absorption solution in the highest partialpressure zone, including the first generator and the resorber.

14. An absorption refrigerating machine, having several differentpartial pressure zones in its constituent vessels, and containing twogenerators, a resorber, an evaporator and two absorbers, one of saidgenerators and said resorber belonging to a high partial pressure zone,and one of the two absorbers and said evaporator belonging to a lowpartial pressure zone, while the other generator and the other absorberbelong to a medium partial pressure zone, connecting pipes to permitcirculation of absorption liquid between said resorber and saidevaporator, connecting pipes for establishing a second liquid circuitbetween said first generator and said second absorber, and connectingpipes for establishing a' third liquid circuit between said secondgenerator and said first absorber, the gaseous working medium in all ofsaid vessels having indiflerent gas admixed to it, connecting pipesbetween said.

evaporator and said first-mentioned absorber for establishingcirculation of gas mixture through the lowest partial pressure zonevessels, connectingpipes between said second generator and said secondabsorber for establishing circulation of gas mixture through the mediumpartial the amount flowing through the other zone, all

liquid circulation pipes between the vessels of the several aforestatedgroupsbeing U-shaped and disposed in'heat exchanging relation to oneanother to circulate absorption solution between the vessel situated ina higher temperature range and the vessel situated in a lowertemperature range, and a heating element in each group of pipes attachedto the upwardly extending leg of the U-pipe leading to the highertemperature vessel for heating the absorption liquid in said leg.

15. In a continuous absorption refrigerating.

system ,using inert gas, an evaporator, an absorber, a plurality ofgenerators, means for circulating inert gas between the evaporator andthe absorber and means for causing inert gas to exert a higher partialpressure in one of said generators than in another of said .generators.

16. In an absorption refrigerating system using inert gas, a pluralityof generators and means for causing the inert gas to exert a higherpartial pressure in one of the generators than in another of saidgenerators. J

1'7. In a continuous absorption refrigerating system using inert gas, agenerator for expelling refrigerant from an absorption solution, anabsorber containing absorption solution, means for causing the solutionin the absorber to absorb the refrigerant expelled in the generator, andmeans using inert gas for causingthe generator to operate over adiiferent solution concentration range than that over which the absorberoperates, said last mentioned means comprising an auxiliary generator,an auxiliary absorber and means for circulating inert gas between theauxiliary generator and the auxiliary absorber. 2

'18. In a continuous absorption refrigerating system, a multi-stagegenerator arrangement consisting of vessels arranged to operate atdifier ent refrigerant pressures and means using inert gas formaintaining different refrigerant pres 2 sures in said vessels.

19. In a continuous absorption refrigerating system, an evaporator, anabsorber, a generator, asecond absorber, a second generator and aresorber so connected as toenable refrigerant to 5 flow in a cycletherethrough in the order named,

present and exerts apartial pressure in at least 45 one of saidgenerators, both of said absorbersand said evaporator- I 21. In acontinuous absorption refrigerating system using an inert gas, anevaporator, an absorber, a generator, a device for changing refrigerantdeveloped in the generator to a more dense fluid phase, means usinginert gas, for conveying refrigerant from said evaporator to saidabsorber, means using inert gas for conveying refrigerant from saidabsorber to said generator,

and means usinginert gas "for conveying therefrigerant from saidgenerator to said device.

- 22. An absorption refrigerating system including as essential elementsa boiler, a device for changing refrigerant from a gaseousoto a'moredense fluid phase, an evaporator, an absorber, a second boiler, a secondabsorber, means for causing' refrigerant to flow through said elementsin 23. An absorption refrigerating system includ- 1 ing as essentialelements, a plurality of generthe order named and means for circulatinginert gas through certain of said elements.

ators, a plurality of absorbers, a device for changing gaseousrefrigerant to a more dense fluid phase, an evaporator and means forcirculating inert gas in a circuit through two of said absorbers, one ofsaid generators and said evaporator.

24. In an absorption refrigerating system, a plurality of boilers, meansfor causing refrigerant to flow through said boilers. in series andmeans for circulating inert gas through one of said boilers. A

25. In an absorption refrigerating system, a

plurality of boilers, a device for changing gaseous refrigerant to amore dense fluid phase, means for causing refrigerant to flow throughsaid boilers and said device in series and means for circulating inertgas between one of said boii- 1U ers and said device.

26. In an, absorption refrigerating system, an absorber, a boiler, asecond absorber and a second boiler, means for circulating absorptionsolu-' tion between said'flrst mentioned absorber and said firstmentioned boiler, means for circulating inert gas between said firstmentionedboiler and said second absorber and means for circulatingabsorption solution between said second absorber and said second boiler.

EDMUND m

